A current leakage event, also known as a ground fault, can occur when an unintended ground, such as water or a human being, comes into electrical contact with one or more electrical circuits of a device. Due to the connection with such ground, current leaks from the device through an unintentional path, which can potentially cause a number of problems, including, for example, fire, damage to system components, or, in the instance that the ground is a person, electrical shock or electrocution.
One attempted solution to the problem of ground faults is the inclusion of a ground fault interrupter in the device. The ground fault interrupter can detect the ground fault condition and interrupt power to the device. Ground fault interrupters can be stand-alone devices or can be built into the hardware of the device.
Ground fault interrupters typically operate by measuring the current leaving the Line side of the power source and comparing it to the current returning to the neutral side. If the difference between these measurements is significant, then it can be assumed that some of the current is flowing along an unintended path and therefore a ground fault event has occurred.
Upon detecting the ground fault, the ground fault interrupter can initiate operations which lead to shutting off power to the device. As an example, the ground fault interrupter can be an integrated circuit that provides a ground fault signal upon detecting the current leakage condition. The ground fault signal can be used to drive an electromechanical relay that will cut power to the entire device.
However, certain existing ground fault interrupter configurations exhibit undesirable behavior that can be frustrating to a user of the device. In particular, once typical ground fault interruption circuits have been tripped, the device will need to be manually reset, requiring a user to make a service call for an electrician or other experienced repair person to identify and resolve the problem.
As another example, if the ground fault interrupter trips a relay or other switch such that power is completely shut off to the device, then the device is unable to perform any “self-diagnosis” or provide the user with any indication of the problem, instructions, or suggested solution.
Therefore, an appliance that provides a more intelligent and user-friendly response to a current leakage event is desirable.